吡嗪酰胺片剂的人体生物等效性

目的 :研究吡嗪酰胺片剂的人体生物等效性与药动学。方法 :2 0名健康受试者交叉口服单剂量 10 0 0mg吡嗪酰胺的2种片剂 ,分别在服药前及服药后 0 .2 5 ,0 .5 ,0 .75 ,1,1.5 ,2 ,4 ,6 ,9,12 ,2 4 ,36h取血样 ,以HPLC法测定吡嗪酰胺的血药浓度 ,并评价其生物等效性。结果 :口服受试制剂与参比制剂的药动学参数 :cmax分别为 (2 1.6 6± 3.0 4 ) ,(2 2 .4 5± 2 .97)mg·L-1;tmax分别为 (1.11± 0 .5 3) ,(1.0 6± 0 .39)h ;消除半衰期 (T1/2 β)分别为 (11.6 5± 2 .80 ) ,(10 .4 7± 1.6 7)h ;AUC0→ 13h分别为 (2 80 .89± 4 1.12 ) ,(2 87.4 3± 4 1.79)mg·h·L-1;AUC0→∞ 分别为 (312 .14± 4 6 .17) ,(315 .92± 5 0 .14 )mg·h·L-1;受试制剂相对生物利用度为 (99.0±16 .9) %。对参数cmax,AUC0→ 13h进行方差分析 ,并进行双单侧t检验 ,tmax经非参数检验均无统计学差异。结论 :2种制剂具有生物等效性     

Amlodipine pharmacokinetics in healthy volunteers

In the present study we investigated the pharmacokinetics and comparative bioavailability of three oral doses of amlodipine in 12 healthy male volunteers. A randomized, open-label, three period crossover study design was employed. Each subject received, on three separate occasions a single oral dose of 2.5, 5 and 10 mg amlodipine. Standing diastolic blood pressure was reduced by 1.1, 4.8 and 8 mmHg six hours after 2.5, 5 and 10 mg amlodipine, respectively. There were no significant changes in pulse rate, nor on the EKG. The curves for the mean plasma concentrations versus time for the three doses showed parallel time-courses. Highly significant positive correlations were observed between dose and AUC (0-72 hrs) and between dose and Cmax. However, dose corrected AUC and Cmax were 10-20% lower with 2.5 mg, than with 5 and 10 mg. Peak levels were achieved 5.6 to 6.4 hours postdose. Half lives were 31.2, 33 and 36.8 hours for 2.5, 5 and 10 mg respectively. Headache was the most common side effect, and was more frequently observed with the highest dose. In summary, linear relationships were found between the dose and the plasma levels of amlodipine. Decreases in standing diastolic blood pressure were also dose related. Because of its long half-life and gradual absorption, amlodipine should be effective in lowering blood pressure given once daily and the incidence of side effects due to rapid absorption should be minimized.     

Clinical pharmacokinetics of the diastereomers of arteether in healthy volunteers

OBJECTIVE: To evaluate the pharmacokinetics of alpha- and beta-diastereomers of arteether in healthy male volunteers. PARTICIPANTS AND METHODS: The study was a single-centre clinical pharmacokinetic trial in healthy male subjects. A group comprising 13 subjects aged 25-50 years received a single intramuscular 150 mg individual dose of the arteether formulation containing alpha- and beta-isomers in a 30:70 ratio. Serial blood samples collected over a period of 0-192 hours were analysed by high-performance liquid chromatography-electrospray ionisation/tandem mass spectrometry and the plasma concentrations were subjected to compartmental and noncompartmental analyses. Pharmacodynamic parameters such as area under the inhibitory curve, ratio of area under the concentration-time curve to minimum inhibitory concentration (AUC/MIC), maximum plasma concentration to MIC (Cmax/MIC) and time that plasma concentration exceeds the MIC (T>MIC) were calculated in vitro in four strains of Plasmodium falciparum to evaluate the in vivo effectiveness of the proposed dosage regimen. RESULTS: There were no adverse effects observed during the study. The extent of metabolism of arteether to dihydroartemisinin (DHA) was low (approximately 5%) so as to be therapeutically nonsignificant. The pharmacokinetic profiles of the arteether diastereomers were different, and the maximum plasma concentrations of alpha- and beta-isomers were reached at 4.77+/-1.21 hours and 6.96+/-1.62 hours, respectively, after which they showed biphasic decline with apparent terminal elimination half-lives of 13.24+/-1.08 hours and 30.17+/-2.44 hours, respectively. The plasma and renal clearances, as well as whole blood to plasma partition ratios of the isomers, were comparable, while the apparent volume of distribution during terminal phase of the beta-isomer was approximately 3-fold higher than that of the alpha-isomer. In vitro erythrocyte culture experiments with four strains of P. falciparum showed similar MICs for both isomers of arteether. The highest observed MIC of 8 microg/L was selected for estimating the pharmacokinetic and pharmacodynamic parameters, which showed excellent correlation with published data on the clinical efficacy of arteether. CONCLUSION: The pharmacokinetics of arteether isomers demonstrated stereoselectivity, which was reflected mainly in the volume of distribution and the terminal elimination half-life. The alpha- and beta-isomers of arteether appeared to compliment each other pharmacokinetically, with the alpha-isomer providing comparatively rapid and higher plasma concentrations resulting in immediate reduction in percentage parasitaemia, while the beta-isomer, with its longer terminal elimination half-life, mean residence time and sustained plasma concentrations, maintained the activity for longer periods. The extent of metabolic conversion of arteether to DHA was minimal, so as to have any therapeutic or toxic significance.     

精氨酸七叶皂苷静脉滴注的健康人体药动学研究

目的:研究注射用精氨酸七叶皂苷健康人体单剂量给药的药动学。方法:采用剂量递增试验设计,30名健康志愿者随机分为3个剂量组,分别静滴注射用精氨酸七叶皂苷5.77 mg,11.54 mg或23.08 mg,用LC-MS/MS同时测定血浆中和尿样中七叶皂苷主要组分的浓度,计算其主要药代动力学参数。结果:健康志愿者单剂量静滴注射用精氨酸七叶皂苷后,七叶皂苷A组分的Cmax分别为(137.7±33.71),(255.9±41.57)和(431.7±104.52)ng.mL-1;AUC0-t分别为(400.9±138.69),(830.8±235.02)和(1 622.9±613.16)ng.h.mL-1;t1/2Ke分别为(2.46±0.53),(3.34±0.42)和(5.66±0.82)h;24 h尿中七叶皂苷A组分累积排出百分率分别为(4.70±1.47),(5.17±1.35)和(5.53±1.85)%。七叶皂苷B组分的Cm ax分别为(74.5±20.87),(141.1±25.64)和(231.8±63.50)ng.mL-1;AUC0-t分别为(196.3±68.22),(381.2±107.60)和(782.7±321.07)ng.h.mL-1;t1/2Ke分别为(2.13±0.68),(2.96±0.79)和(4.88±1.18)h;24 h尿中七叶皂苷B组分累积排出百分率分别为(2.54±0.71),(2.69±0.59)和(3.12±1.17)%。结论:健康人体单剂量静滴注射用精氨酸七叶皂苷5.77～23.08 mg剂量范围内,七叶皂苷A组分和B组分的Cm ax,AUC0-t和t1/2Ke均随着剂量的增加而增加。     

龙胆苦苷在健康受试者尿中的药代动力学

目的 研究中药龙胆苦苷(保肝、利胆中药活性成分)在健康受试者尿中的药代动力学.方法 筛选12名健康受试者按双拉丁方设计,分别静脉滴注龙胆苦苷80、240、400 mg,用LC/MS/MS法测定各时段的尿药浓度,用WinNonlin软件计算尿药代动力学参数.结果 3个剂量下原药的最大尿排速率分别为20.5、60.8、105.5 mg·h-1(tmax为0.75 h),尿排速率-时间曲线下面积分别为51.1、144.7、269.8 mg;25.5 h累积尿排量分别为61.3、172.7、319.1 mg,经统计均与剂量呈正比;t1/2分别为2.96、2.90、2.90 h,消除速率常数k分别为0.25、0.26、0.25 h-1;3个剂量的平均25.5 h累积尿排率为76.1%,其中0～7.5 h占总排泄量的96.2%.结论 龙胆苦苷在人体内主要以原形经肾脏快速排泄,在80～400 mg内呈线性药代动力学特征.     

Multiple-dose pharmacokinetics of nilvadipine in healthy volunteers

Nilvadipine, a new antihypertensive and antianginal drug, was studied in six healthy male volunteers to evaluate its steady-state pharmacokinetics after oral dosing. The subjects were given a single dose of 4 mg, followed by 4 mg every 12 hours for six days after a washout period of more than 3 days. The pharmacokinetics of nilvadipine were well described by a linear model of triexponential equation with zero-order absorption. The steady state was reached by the fourth day of multiple dosing, with a twofold accumulation of trough plasma concentration and no accumulation of peak concentration. The mean plasma concentration at steady state was 1.0 ng/mL. The optical enantiomers of nilvadipine were also determined in the plasma. The plasma concentration of (+)-nilvadipine was about two and a half times higher than that of (-)-nilvadipine, and this ratio was unaffected by multiple dosing.     

Single-dose pharmacokinetics of fenquizone in healthy volunteers

A pharmacokinetic study of fenquizone (Idrolone), a thiazide-like diuretic, was conducted with single oral doses in 6 healthy volunteers. The substance thus administered was readily absorbed from the gut, with peak plasma levels being detected on average at 3 h after dosing; after that, plasma concentrations of fenquizone decreased biexponentially in a pattern fitting an open two-compartment model. Plasma half-life values were 1 h for phase alpha and 17 h for phase beta. The half-life calculated from urinary concentrations was 18 h. The apparent distribution volume for phase beta was 686 l; renal clearance was 220 ml/min, and the absorption constant (Ka) was 1055 h-1. Cumulative urinary excretion accounted for 53.1% of the administered dose in 72 h. Thus the pharmacokinetic profile of fenquizone was that of an "intermediate-acting" diuretic about half-way between the short-acting hydrochlorothiazide, chlorothiazide and furosemide and the long-acting chlorthalidone. In summation, fenquizone is described as a low-dosage diuretic apparently not conducive to accumulation; its pharmacokinetic profile qualifies the product particularly well for maintenance therapy, such as is needed for the management of essential hypertension, both as sole medication and in fixed-ratio combination with beta-blockers, and at any rate with once-a-day administration.     

Dose-dependent pharmacokinetics of aprindine in healthy volunteers

Summary The disposition of aprindine following a single oral dose can best be described by a two-compartment open model. The mean plasma half-life (t_1/2) increased from 8.0±2.1 h (SD) after a 25 mg dose to 9.4±2.9 h after 50 mg and to 15.8±2.6 h after 100 mg, with a decrease in total plasma clearance (Cl/F) and volume of distribution at steady state (V_dss/F) and during -phase (V_d/F). The area under plasma concentration-time curve (AUC), maximum plasma concentration (C_max) and the amount of unchanged aprindine excreted in the urine increased in a non-linear fashion with the increase in dose. The t_1/2 after multiple oral doses showed a 3-fold increase over the single dose value. These results indicate that aprindine shows dose-dependent non-linear kinetics.     

Population pharmacokinetics of tigecycline in healthy volunteers

Tigecycline, a novel glycylcycline, possesses broad-spectrum antimicrobial activity. A structural population pharmacokinetic model for tigecycline was developed based on data pooled from 5 phase I studies. Intravenous tigecycline was administered as single (12.5-300 mg) or multiple (25-100 mg) doses every 12 hours for up to 10 days. Three-compartment models with zero-order input and first-order elimination separately described the single- or multiple-dose full-profile data. Additional models were evaluated using a subset of the phase I data mimicking the phase II/III trial sparse-sampling scheme and dosage. A 2-compartment model best described the reduced phase I data following single or multiple doses and provided reliably accurate estimates of tigecycline AUC(0-12). This modeling supported phase II/III population pharmacokinetic model development to further determine individual patient tigecycline exposures for safety and efficacy analyses.     

Concomitant cyclosporine and micafungin pharmacokinetics in healthy volunteers

Cyclosporine is a marketed immunosuppressive agent and a known substrate for CYP3A. Micafungin is an antifungal agent and a mild inhibitor of CYP3A-mediated metabolism in vitro. The objectives of this study were to evaluate the pharmacokinetics of cyclosporine and micafungin before and with concomitant administration. The pharmacokinetics of single-dose oral cyclosporine (5 mg/kg) were estimated on days 1, 9, and 15 (n = 27). Subjects received micafungin (100 mg/d over 1 hour) on days 7, 9, and 11 through 15. Micafungin pharmacokinetics were estimated on days 7, 9, and 15. Mean apparent oral cyclosporine clearances were estimated to be 645+/-236 mL/h/kg, 546+/-101 mL/h/kg (P = .01), and 540+/-104 mL/h/kg (P = .02) for days 1, 9, and 15, respectively. Micafungin appears to be a mild inhibitor of cyclosporine metabolism.     

Concomitant tacrolimus and micafungin pharmacokinetics in healthy volunteers

Tacrolimus is an approved immunosuppressive agent and a known substrate for CYP3A. Micafungin is an echinocandin antifungal agent and a mild inhibitor of CYP3A metabolism in vitro. The objectives of this study were to evaluate the pharmacokinetics of tacrolimus (5 mg oral) and micafungin (100 mg intravenous) alone and with concomitant administration (n=26). Tacrolimus area under the concentration-time curve was 298+/-135 microg*h/L when tacrolimus was administered alone, 305+/-129 microg*h/L (P=.8; confidence interval 89%, 118%) when tacrolimus was given with single-dose micafungin, and 282+/-138 microg*h/L (P=.4; confidence interval 82%, 107%) when tacrolimus was given with steady-state micafungin. Despite the mild inhibition of CYP3A in vitro by micafungin, there does not appear to be a drug interaction with tacrolimus and micafungin either with single-dose or steady-state micafungin administration.     

Alcohol and bupropion pharmacokinetics in healthy male volunteers

Summary A study was performed to determine whether there is a pharmacokinetic interaction between alcohol and the novel antidepressant bupropion. In the first part 8 healthy male volunteers received single doses of 100 mg bupropion hydrochloride orally on 2 occasions accompanied by either ethanol in orange or plain orange drink according to a balanced cross over design. Plasma bupropion concentrations were determined by radioimmunoassay and kinetics analysed with the aid of NONLIN. Blood alcohol levels were assessed by breathalyser. The disposition of bupropion was adequately described by a 2 compartment model and kinetic parameters were not significantly altered by the presence of alcohol. In the second part of the study the same subjects received 40 ml ethanol in orange drink 3.5 h after ingestion of 100 mg bupropion or dummy tablet in a double blind cross over fashion. Bupropion did not affect alcohol kinetics. In contrast to many other psychotropic drugs there is no evidence for a kinetic interaction between bupropion and alcohol.     

健康男性志愿者体内阿那曲唑生物利用度和药代动力学研究

目的　比较国产和进口阿那曲唑片在健康人体内的生物利用度和药代动力学。方法　二十名中国健康男性志愿者随机交叉单剂量口服 2mg国产和进口阿那曲唑片 ,用GC ECD法测定血药浓度。血药浓度测定的线性范围为1 32 5～ 10 6 μg·L-1。低、中、高血药浓度 (5 3、2 1 2、5 3 0 μg·L-1)提取回收率分别为 76 8%、87 0 %、78 7%。天内和天间精密度均小于 9%。通过方差分析和双单侧t检验比较两种制剂的药—时曲线下面积 (AUC0 -t)、最大血药浓度(Cmax)和达峰时 (Tmax)。结果　阿那曲唑的体内分布符合二室模型。国产和进口阿那曲唑的药动学参数Cmax分别为(36 5± 6 9)和 (35 6± 9 4 ) μg·L-1;Tmax分别为 (1 5 6±0 4 1)和 (1 5 3± 0 4 9)h ;AUC0 -t分别为 (14 0 3 6± 32 1 2 )和 (1371 6± 32 9 4 ) μg·h·L-1,T1/ 2 β分别为 (42 5 7± 10 15 )和 (43 4 1± 8 5 9)h。经t检验做等效性判断 ,说明两制剂具有生物等效性。结论　两种制剂为生物等效 ,国产阿那曲唑片的相对生物利用度为 (10 2 7± 5 6 ) %。     

国产氧氟沙星在健康成人中的药物动力学和生物利用度研究

本文采用专一性强、灵敏度高的HPLC 荧光检测法,测定氧氟沙星血、尿浓度。对国产氧氟沙星片在12例健康受试者中进行药物动力学和生物利用度研究。氧氟沙星片口服给药多数人为一房室模型,其主要药动学参数,国产片和进口片分别为:T_(1/2)6.2±1.3和6.1±1.5h;Vd 1.5±0.4和1.6±0.5l/kg;C_(max)8.6±2.5umol/L 和7.9±1.4μmol/L;T_(max)0.6±0.5和0.6±1.0h;Cl_T13±4和12±4 l/min;AUC_(o-∞)76±23和73±21μmol/L·h。其相对生物利用度为104.9±9.9%。     

劳拉西泮片人体生物等效性研究

目的:进行劳拉西泮片试验与参比制剂单剂口服双交叉试验,研究其生物等效性.方法:健康志愿者20名随机分两组,随机交叉自身对照,高效液相色谱法测定劳拉西泮经时血药浓度,数据经DAS程序处理,得劳拉西泮片药动学参数.结果:劳拉西泮试验制荆和参比制剂主要药动学参数t1/2分别为(19.7±2.0)h和(18.9±1.7)h,tmax分别为(2.58±0.18)h和(2.60±0.21)h,Cmax分别为(24.8±4.0)μg·L-1和(24.6±3.6)μg·L-1,AUC0-60分别为(628.2±90.7)μg·L-1·h和(636.2±62.6)μg·L-1·h,AUC0-∞分别为(718.1±84.6)μg·L-1·h和(722.9±57.9)μg·L-1·h.试验制剂劳拉西泮片相对生物利用度F为(98.7±8.8)%.试验与参比制剂AUC0-∞、AUC0-60、tmax、t1/2、Cmax方差分析、双向单侧t检验显示,主要药动学参数周期问、剂型间差异无显著性(P＞0.05).结论:劳拉西泮血药浓度测定方法适用;试验制剂与参比制剂具有生物等效性.     

螺内酯片在健康人体内药代动力学及生物等效性

目的 研究螺内酯片(利尿药,抗高血压药)在健康人体内的相对生物利用度,并进行生物等效性评价.方法 采用随机交叉自身对照试验设计,18名健康男性受试者分别单剂量口服螺内酯受试制剂或参比制剂25 mg后,取静脉血,采用HPLC-MS法测定其活性代谢产物坎利酮的血浆浓度,计算主要药代动力学参数.以方差分析进行均数的差别检验,以双单侧t检验进行生物等效性判定.结果 受试者分别口服受试制剂和参比制剂后,坎利酮的主要药代动力学参数如下:AUC0→72分别为(684.8±184.4)、(682.1±212±7)μg·h·L-1,AUC0→∞分别为(803.8±249.6)、(774.3±259.3)μg·h·L-1,tmax分别为(2.1±0.3)、(1.9±0.4)h,Cmax分别为(51.3±12.4)、(54.1±12.9)μg·L-1,t1/2分别为(25.0±9.2)、(22.1±6.0)h.受试制剂对参比制剂的相对生物利用度为(102.2±19.0)%.结论 受试制剂与参比制剂为生物等效制剂.     

茴拉西坦胶囊健康人体生物等效性与药代动力学研究

目的 研究两种茴拉西坦胶囊在健康中国人体的生物等效性.方法 20名健康志愿者随机分为试验组和对照组,采用双交叉设计和单剂量口服方式,HPLC法测定血清中茴拉西坦活性代谢产物对甲氧基苯甲酰氨基丁酸(ABA)血药浓度).经DAS2.0统计软件处理,计算主要药代动力学参数,并进行两种制剂的生物等效性评价.结果 口服600 mg受试制剂和参比制剂后,其主要活性代谢物ABA的血清t1/2分别为(0.63±0.25)h和(0.86±0.59)h,Cmax分别为(14.81±3.26)mg/L和(15.84±2.89)mg/L,Tmax分别为(0.68±0.25)h和(0.60±0.19)h,AUC0～3.5 h分别为20.33±4.58和(20.86±5.76)mg·h-1·L-1.受试制剂的相对生物利用度为(101.14".05%).结论 两种茴拉西坦胶囊具有生物等效性,临床上可替代使用.     

来氟米特在中国健康人群中的群体药动学研究

目的：建立来氟米特口服给药在中国健康受试者体内的群体药动学模型,探讨其药动学特征及可能的影响因素。方法：21名健康男性受试者参与本次研究,应用Phoenix NLME（Vision 8.0）软件中的群体模块分析来氟米特口服给药后其代谢产物的血药浓度数据,估算相关药动学参数及其变异情况。结果：来氟米特活性代谢产物特立氟胺在健康志愿者中符合一级吸收的一室模型。吸收速率常数K_a、分布容积V、药物清除率CL的群体典型值分别为0.691 h^-1、12.843 L和0.031 L·h^-1。协变量筛选结果显示,BMI对分布容积V有显著影响（P<0.01）。结论：本研究成功建立了来氟米特在中国健康人群中的群体药动学模型,最终模型可对个体药代参数做出精确的估计,BMI对分布容积V有显著影响。     

Metabolism and pharmacokinetics of 14C-pentoxifylline in healthy volunteers

The metabolism and pharmacokinetics of 14C-pentoxifylline (Trental) have been studied in three healthy male volunteers after oral administration of 200 mg (50 microCi). The radiolabelled drug was rapidly absorbed and by 6 h 89.1 +/- 2.4% of the 14C material was excreted in the urine. The dosed 14C material (96.9 +/- 2.2%) was recovered in excreta by 24 h with 93.3 +/- 2.3% in the urine 3.0 +/- 0.2% in the faeces. Peak plasma levels of radioactivity (4.1-6.2 micrograms eq ml-1) occurred 0.25-0.75 h after administration. This radioactivity decayed in a biexponential fashion with an initial half-life of 1.01 +/- 0.13 h and a terminal half-life of 36.06 +/- 16.94 h. The peak plasma levels (0.48-2.25 micrograms ml-1) of parent drug, as measured using a specific gas chromatographic assay also occurred at 0.25-0.75 h and subsequently decayed extremely rapidly with an initial half-life of 0.18 +/- 0.15 h and terminal half-life of 0.76 +/- 0.44 h. Urinary 14C-labelled metabolites were separated by semi-preparative high performance liquid chromatography and characterised by mass spectrometry and by comparison with authentic synthetic compounds. Of the dosed 14C-pentoxifylline, greater than 90% could be identified as characterised metabolites in urine.